Frank stuart smith



(No Model.)

P. S. SMITH.

APPARATUS FOR TREATING FILAMENTS.

No. 404,118. A Patented May 28, 1889.

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WITNESSES! XNVENTOR.

j FRANK STUART SMITH- Att' y,

' UNITED STATES PATENT OFFICE,

FRANK STUART SMITH, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THE ESTINGHOUSE ELECTRIC COMPANY, OF SAME PLACE.

APPARATUS FOR TREATING FILAMENTS.

SPECIFICATION forming part of Letters Patent No. 404,118, dated May 28, 1889.

Application filed March 12, 1889. Serial No. 303,032. (No model.)

To aZZ whom it may concern.-

Be it known that I, FRANK STUART SMITH, a citizen of the United States, residing in the city of Pittsburg, county of Allegheny, and State of Pennsylvania, have invented a new and Improved Apparatus for Treating Filaments for Incandescent Electric Lamps, (Case No. 299,) of which the following is a specification.

The invention relates to an organization of apparatus for treating and preparing filaments for incandescent electric lamps. Such filaments, after they have been carbonized and before they are pla eed in the lamp-bulbs,

are usually heated by electric currents while surrounded by 'an atmosphere of hydrocarbon gas. The resistance of a filament is gradually reduced during this process, and when it has decreased to a predetermined point it is desirable that it shall be automati= cally removed from the electric circuit. Heretofore it has been customary to employ continuous electric currents for so heating the filaments, and the strength of the current has been controlled by means of an adjustable artificial resistance or in some other suitable manner. Some form of automatic cut-out has also been used for the purpose of automatically cutting off the current from the 3 filaments at the proper moment.

My invention consists in employing, in connection with alternating electric currents for heating the filaments, devices whereby any required electro-motive force may be readily obtained from a given source of current and the treatment caused to cease at the proper moment and devices whereby the same source of currents may be utilized for conducting various different operations entirely independently of each other.

A special feature of the invention consists in the employment of reactive coils or selfinduction devices, through which the current is transmitted to the filaments. These coils serve to regulate or govern the currents auto matically in a useful and desirable manner. They are so proportioned that as the currents are first applied to the filaments the coefficient of self-induction is comparatively low, but as the resistance of the filaments dccreases and the currents flowing tend to increase the coefiicient of self induction increases, allowing less current to pass. This greatly facilitates the application of the eurrents to the filaments and keeps the filaments 5 5 at an approximately constant temperature, and serves at the same time to render more uniform the point at which the circuit-interrupting devices are brought into action-a result which is of importance, for the reason that it is desirable that all of the filaments should have as nearly as possible the same amount of resistance when finished, or, in other words, that they shall be cut out of the circuit and the treatment caused to cease at the moment resistance has fallen to a givenv point.

In another application, Serial No. 278,661, filed June 30, 1888, claim is made for the combination of a source of alternating cur- 7o rents and a treating-chamber containing a filament in the circuit of such source.

In the accompanying drawing there is shown in diagram an organization of apparatus, as employed in a treating-room, utilizing alternating currents in the manufacture and preparation of filaments for incandescent electric lamps.

Referring to the figure, A represents a source of alternating, intermittent, or pulsa- 8o tory electric currents, and L L lines leading therefrom. Converters B, B and B have their primary coils connected in a multiple are between the lines L and L The secondary coils of these converters supply subsidiary conductors a a? a a a a. These conductors maybe regarded as supplying different sets of treating apparatus or serving to supply currents of the proper elect-ro-motive forces to be used for different purposes in the treating-room. Thus the difference of potential between the lines L and L may be one thousand volts and the converter B so constructed as to deliver to the lines a a currents of one hundred volts,while the converter B delivers currents to the lines a a of two hundred volts and the converter B delivers currents of twenty-five volts to the lines a a. These relative values, however, maybe varied,

as found convenient, for different purposes. IOO

' in the position shown in the drawing.

A conductor, 1), leads from the conductor a, through a reactive coil, H, to a clamp or binding-post, e, which is designed to receive one end of a filament, f. The other end of this filament is carried in a clamp, 6 which is connected by a conductor, b through a circuit interrupting device, in a manner presently to be described, with the conductor a The filament is inclosed in a chamber, 1V in which it can be surrounded by an atmosphere of hydrocarbon in a manner well understood. Inlet and outlet pipes K and K are provided for exhausting the air and admitting the gas to the chamber. While the filament is surrounded by asuitable artificial atmosphere, or while being otherwise treat-ed, it is necessary to control the current transmitted through it. For this purpose the coils h of a self-induction device or reactive coil, H, are included in the conductor 1). The currents traversing this coil are opposed to a greater or less extent by the counter electro-motive force generated within the coil and due in great part to the presence of a core, h, of soft iron. The reactive eifect of the coil may be controlled by means of a switch, t,which serves to include more or less of the length of the coil in circuit, as required, or the core may be adjustable in the coil.

For the purpose of automatically cutting the filament out of the circuit when the resistance thereof has decreased to a certain predetermined point, an automatic cut-out, G, is

employed. This may consist of any wellknown form of circuit-interrupter adapted to the purpose. In the present instance there is shown a device consisting of two opposing coils, g '9 acting upon the pivoted lever G, and provided with movable cores supported from the respective ends of a circuit-closing arm, 70. The coil g is included in the circuit between the conductor 19 and the clamp c and the coil g is included in a shunt-circuit, b extending around the filament and coil g. The circuit including the filament is completed through the arm k and its restingpoint by the lever 9 when the parts are If, however, the right-hand end of the lever is drawn down, then the arm 70 is thrown away from the point 70 by a spring, o, thus interrupting the circuit-connections through the filament. An adjustable resistance, B, may be included in the conductor b for the purpose of readily balancing the effects of the coils gg The parts are so organized that so long as the resistance of the filament is above the predetermined point the current traversing the coils 9 will be sutficient to hold the lever against the resting-point 9 When, however, the resistance has decreased to this predetermined. point, then the increase of current flowing through the filament and the coil g will move the lever, releasing the circuit-breaking arm k. This also looks the lever g in its second position. By adjusting the effect of the coil h any desired electro-motive force may be employed for treating the filament f.

At M there is shown a second treatingchamber, and this is equipped with a reactlve coil, H and a circuit-controlling device, G similar to those already described. The currents for this treating apparatus are derived from the conductors a (1 but different electro-motive forces may be employed from those employed in connection with the first-named apparatus. For instance, filaments designed for sixteen candle power lamps may be treated in the chamber N while filaments for twenty-candlepower lamps are being treated in the chamber M the currents belng derived from the conductors a and a inclependently of each other. sired to treat other filamentsfor instance, for fifty and one hundred candle -power lamps-by currents from the same source, then treating apparatus M and M may be supplied with the requisite currents from the conductors a and a independentlyof each other.

A further step in the operation of treating the filaments, which it is found convenient to carry on in the same room with the depos tion of carbon, is the cementing of the termlnals of the filaments into the ends of the leading-in wires. For this purpose it is customary to place the filament in a bath of some hydrocarbon liquid and heat the portions upon which it is desired to deposit the carbon by means of electric currents. Apparatus I01 this purpose is represented at P and P and the currents required therefor are derived from the conductors a a. The converter B is organized to deliver to these conductors a current of the required difierence of potential independently of the converters supplying the currents for the other operations described. Diiferent Ways of carrying out this portion of the invention may be adopted. In the present instance there is shown a conductor, 1), leading from the conductor a to one terminal of the filament f which is placed in the bath, While the other terminal of the filament is connected by the conductor 13* with one terminal of the adjustable resistance R. A circuit-closing bar, r, provided with a handle, r, of insulating material,is electrically connected by the conductor 19 with the conductor a. During the operation of cementing, the resistance included in the circuit may be varied by sliding the bar 1" along to the resistance R, thereby gradually increasing the resistance in circuit as the resistance at the points being cemented decreases.

Other operations pertaining to the preparation and treatment of filaments may be carried on in the general manner described, the requisite currents being obtained, as described. The description given will, however, serve to show the general plan and purposeof the invention.

I claim as my invention- 1. In an apparatus for treating filaments for If, now, it is de' incandescent electric lamps, the combination of a source of alternating electric currents, supports or electrodes for the respective ends of the filaments, conductors leading thereto from the source, and a reactive coil included in one of the said conductors.

2. In an apparatus for treating filaments for incandescent electric lamps, the combination of a source of alternating currents, electrodes for receiving the respective ends of a filament, conductors leading thereto, a reactive coil included in one of said conductors, and an automatic circuit-interrupting device, also included in one of said conductors.

3. In an apparatus for treating filaments for incandescent electric lamps, the combination of a source of alternating electric currents, electrodes for receiving the respective ends of the filaments, conductors leading thereto, and a reactive coil included in one of said conductors, Whose coeflicient of selt-induction increases as the resistance of the filament decreases, substantially as described.

at. In an apparatus for treating filaments for incandescent electric lamps, the combina tion of a chamber for receiving the filaments, a source of alternating electric currents, an electric circuit therefor having its terminals Within said chamber, and an adjustable reactive coil included in said circuit.

5. The hereinbeforedescribed organization of apparatus for treating filaments forincandescent electric lamps, consisting of two or more treating-chambers, circuits for supplying alternating electric currents thereto of different electro-motive forces, and a single source of alternating electric currents supplying said circuits.

6. An organization of apparatus for treating filaments by alternating electric currents, consisting of a source of alternating electric currents, electric converters deriving currents from said source independently of each other, independent treating-circuits derived from the respective secondary circuits of said converters, independent treating apparatus included in said secondary circuits, and reactive coils included in the respective treatingcircuits.

7. The combination, with a treating apparatus for the filaments of incandescent electric lamps, consisting of a source of alternating electric currents, a circuit derived therefrom in which said filaments may be connected, and a reactive coil connected in said circuit, of apparatus for cementing or otherwise treating the filaments, also receiving currents from the said source, substantially as described.

In testimony whereof I have hereunto subscribed my name this 6th day of March, A. D. 1889.

FRANK STUART SMITH.

Vitn esses:

W. D. Urrnenarn, CHAnLns A. TERRY. 

